The present invention relates generally to laser spotlights, and more particularly to a finger mounted near-infrared laser spotlight for use by helicopter pilots wearing night vision goggles.
Helicopter pilots flying at night wear night vision goggles, or other night vision equipment, to see at very low light levels. Night vision goggles are primarily image intensifiers having a response curve that peaks at near-infrared light wavelengths. With experience, a helicopter, or rotary wing aircraft pilot, becomes adept at recognizing objects by their near-infrared image as displayed in night vision goggles. In many situations, however, particularly during dead-of-night landings and rescue operations, precisely locating objects becomes critically important to avoid an accident. There is often an insufficient near-infrared image available from objects on the ground. Shadows and other dark regions make the pilot's situation even more hazardous.
An object can be illuminated by a beam of near-infrared light in the same manner as illuminating an object with visible light. So too can shadows and other dark regions be illuminated with a beam of near-infrared light. The near-infrared light beam and the near-infrared light reflected from the object or dark region will be visible to pilots wearing night vision goggles, but will still be invisible to the naked eye.
Unfortunately, the solution to the problem of nighttime helicopter landings and rescues is not merely as simple as providing helicopter pilots with a near-infrared spotlight. Helicopter pilots are already so busy operating their controls in a fast changing environment that a near-infrared light source enclosed, for example, inside a conventional flashlight body that has to be grabbed, turned on and held, will not adequately help them make safe nighttime landings or perform other nighttime tasks.
The prior art includes examples of wrist mounted flashlights that produce a beam of visible, generally near-white or yellow, light. The prior art even includes an ornamental design patent for a finger mounted flashlight. These prior art flashlights mount on a wrist or a finger so that the direction of their visible light beam can be easily changed while keeping the hands otherwise free.
Applicants' invention, as described in the Detailed Description, combines for the first time a finger mount with a near-infrared light source. Unfortunately, solving the problem of providing a usable near-infrared spotlight for helicopter pilots is not as easy as simply strapping a near-infrared light source onto a finger. The prior art wrist and finger mounted visible light flashlights include conventional flashlight switches intended to be switched on and left on. This is adequate for those flashlights because, for the close-up uses for which they are intended, the low intensity beams required for those uses do not use much electricity and can stay lit for a long period of time without quickly draining their batteries. A near-infrared spotlight suitable for use in a helicopter, needs to be able to emit a relatively bright, near-infrared beam and still be ready for use over extended periods of time without having to replace its battery. Moreover, in the hostile environment in which such helicopter pilots fly, a continuously on spotlight can be a beacon to an enemy equipped with night vision goggles. Perhaps most importantly, a near-infrared spotlight bright enough to be useful can harm unprotected eyes at both close and medium ranges. It would be dangerous to have a bright, finger mounted near-infrared light source continuously on while a helicopter pilot's hands move about the cockpit or while the pilot surveys a rescue landing site.
Thus it is seen that there is a need for a finger mounted near-infrared light source suitable for use by helicopter pilots wearing night vision equipment.
It is, therefore, a principal object of the present invention to provide a finger mounted near-infrared light source that is safe, effective and accepted by helicopter pilots.
It is another object of the present invention to provide a finger mounted spotlight that projects a beam of non-visible light.
It is a feature of the present invention that it includes safety features to help prevent injury to unprotected eyes.
It is an advantage of the present invention that it uses commercially available off-the-shelf electronic components and can be quickly assembled by personnel with minimal training.
It is another advantage of the present invention that it is simple to use.
These and other objects, features and advantages of the present invention will become apparent as the description of certain representative embodiments proceeds.